A recent revival in interest in bicycling has generated a demand for bicycles and bicycle parts, including bicycle frames, in which demand has exceeded the supply. Because the existing manufacturing techniques used in manufacturing conventional bicycle frames make it difficult for manufacturers to quickly increase their capacity, the increased demand for bicycle frames remains unsatisfied and has resulted in an increase in cost.
Conventional bicycle frames are formed of a plurality of tubular members and lugged frame joint fittings that must be individually fabricated and then individually assembled to form the complete frame. The latter process includes assembling the lugged frame joint fittings and the tubular members in a welding and/or brazing the tubular members in the lugged joints, cleaning and grinding the arc welds to form smooth junctions, priming the assembled frame to prevent rust, and, finally, applying the finishing coats of paint. This process is slow and labor intensive and the labor/material cost ratio is high. Thus, a frame that could be fabricated faster and with considerably less expenditure of labor, especially one amenable to automated techniques, would be considerably cheaper and would be most welcome in the industry.
The assembly of the frame components in a welding jig must be performed with considerable care to assure accurate alignment. If the frame is misaligned, the front wheel will track in a non-vertical plane, with the result that bicycle will tend to veer off to one side. Consequently, the rider must continually compensate to hold the bicycle on course, and such a bicycle is tiring to ride and difficult to handle. A bicycle frame that is intrinsically perfectly aligned would eliminate this troublesome problem and would represent a substantial advancement in the art.
The welded or brazed junctions of conventional tubular frames are the most frequent points of failure in conventional bicycles along with scrapes on the painted surface that open bare metal to air and water and—result in rust formation that can spread and disfigure and ultimately weaken the frame unless corrective steps are taken. Thus, a bicycle frame formed of an inert material that would be immune to rust would not require the priming and painting steps. The savings from elimination of the priming and painting steps could be passed on to the buyer, and this in combination with the freedom from maintenance necessary for conventional bicycles would make such a bicycle frame more desirable by a rider. Thus, an inexpensive bicycle frame which could be fabricated of a light and strong material would be greatly welcomed by the industry and the bicycling public.